Changes of Antioxidant Function and the mRNA Expression Levels of Apoptosis Genes in Duck Ovaries Caused by Molybdenum or/and Cadmium

Abstract

To investigate the effects of molybdenum (Mo) combined with cadmium (Cd) on the antioxidant function and the mRNA expression levels of apoptosis-related genes in duck ovaries, 60 healthy 11-old-day female ducks were treated with hexaammonium molybdate ([(NH4)6Mo7O24·4H2O]) or/and cadmium sulfate (3CdSO4·8H2O) at different doses on a daily basis for 120days. On the 120th day, ten female birds in each group were euthanized, and the ovaries and blood were collected to determine the antioxidant indexes and the mRNA expression levels of Bak-1, Bcl-2, and caspase-3 in ovaries. In addition, ovary tissues were subjected to histopathological analysis with optical microscope. The total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity decreased significantly (P < 0.01) in treated groups comparing with control while the nitric oxide synthase (NOS) activity increased (P < 0.01) both in ovary tissue and serum. The Bak-1 and caspase-3 expressions were upregulated while the Bcl-2 was downgraded by Mo or/and Cd. Biomolecules were affected in all metal-treated groups, whereas combined-treated animals showed greater effects. What is more, pathological damage in Mo and Cd combination treated groups was more severe. The results from the present study indicated that Mo or/and Cd caused oxidative stress and apoptosis in duck ovaries. Combination of Mo and Cd showed additive or synergistic effect leading to apoptosis and oxidative stress, and the pathway might be the mitochondrial pathway.